Wound healing failure, would infections, and excessive, noncompliant scars continue to be major limiting factors in survival and rehabilitation from trauma and significant contributors to the crippling effects of a host of other diseases. In this application, we propose to continue our long-term pursuit of the role of oxygen, oxidants, and growth factors/cytokines in would healing and resistance to infection with the overall goals of elucidating mechanisms of repair and learning how to ensure salutary repair. We propose to focus mainly on the metabolic state of the wound environment, how it regulates collagen synthesis and angiogenesis, the manner in which redox-related events induce and modulate the effects of growth factors/cytokines, and the contributions that oxygen, oxidants and antioxidants make to resistance to infection. We propose a four part strategy. In this project, we examine the concept that collagen synthesis and angiogenesis are 'redox regulated' by the lactated, hypoxic, acidotic, microenvironment generated by inflammatory cells in under-perfused, i.e. injured tissue. We postulate that this environment acts via adenosine diphosphoribosylation (the ADPR system) in fibroblasts, macrophages and endothelial cells by invoking expression of some growth factors, and providing points of influence for others. We will examine the influence of lactate, NAD+, inhibitors of ADP-ribosylation, and oxidant radicals on collagen gene transcription. We will determine whether the well known hypoxic induction of angiogenic growth factors is mediated by ADP ribosylation. We will similarly examine production and regulation of heat shock proteins as a potential part of the mechanism of healing. Our goal is to test a concept of 'healing' in which a variety of reparative phenomena may be integrated by a common linkage to metabolic (redox) mechanisms. In this project we focus on how insulin-like growth factor (IGF-1) expression may respond to these same environmental signals and then participate in stimulating collagen synthesis through ADP- ribosylation mechanisms and protein kinase phosphorylation. We plan also to examine the acute responses of IGF-1 and several of its binding proteins to trauma and burns, both locally and systemically, with the ultimate goals of using IGF, its binding proteins, and their complexes to ensure acute phase repair and possible to modulate excessive scarring after injury. In this project we propose to investigate oxidant production and antioxidant defenses of leukocytes with the aim of enhancing intracellular bacterial killing of bacteria through extension of neutrophil oxidative burst activity, particularly in diabetics. The strategy will be to inventory the intracellular antioxidant defenses and to devise means to optimize these defenses by assuring that leukocytes are protected against the lethal effects of the oxidants that they produce. Working in collaboration with project 1, these investigators will study also the effects of uncompartmentalized, unexpected oxygen radicals on the ADPR system in light of their ability to pathologically instigate collagen synthesis/deposition, cytokine expression, and other aspects of wound pathology. In this project, we will continue to identify obstacles to oxygen transport to wounds of animals and man and to develop means of correcting them, again with the aim of ensuring repair and resistance to infection. The major methods in this section are the optical measurement of PO2 in tissues and wounds and the measurement of collagen deposition and other components of wound healing in wounds of animals and man. In general, standard molecular techniques, wound assays, and angiogenesis models will be used.